Abstract

Magnetization as a function of temperature and field has been measured with field parallel or close to ab-plane geometry in single crystals of Nd1.85Ce0.15CuO4−y. For fixed magnetic fields, anomalous temperature dependence of magnetization is observed. For fixed temperatures, the magnetization shows abrupt changes to almost zero value above some critical field, an indication of magnetic transparent state. The data deviates from the conventional Abrikosov theory for type-II superconductors. Instead, the results support the picture of Josephson decoupling between the superconducting layers.